In a next-generation 5G system, massive machine type communications (MTC) for maintaining massive connection and sporadically transmitting a short packet have been considered. The massive MTC service has very high connection density requirement, whereas data rate and end-to-end (E2E) latency requirement is very free (Connection Density: Up to 200,000/km2, E2E Latency: Seconds to hours, DL/UL Data Rate: typically 1-100 kbps).
Currently, with regard to cellular Internet of things (IoT) that has been discussed in 3GPP GRAN, technologies in a model in which about 50000 or more user equipments (UEs) are present in one cell have been developed.
However, a detailed method of effectively supporting a massive sporadic packet based on multi-user access has not been proposed thus far.